Lean-catalyst LiF/Co heterointerface: Unlocking efficient prelithiation for high-energy-density lithium-ion batteries

Developing high-capacity cathode prelithiation agents remains challenging due to severe kinetic limitations, high operational voltages, or insufficient stability in conventional materials. To address this, we report a cobalt-decorated lithium fluoride composite (S-LiF/Co, with a Co content of 15.76 wt% by ICP-OES) synthesized via a scalable solid-state route. The in situ formed LiF/Co heterointerface serves as a catalytic center, which, as evidenced by theoretical calculations, effectively weakens LiF bonds and significantly lowers the energy barriers for both Li⁺ migration and LiF decomposition. This enables S-LiF/Co to deliver a high initial charge capacity of 886.23 mAh g^-1. When incorporated into NCM811 cathodes, it substantially promotes a stable, LiF-rich cathode electrolyte interphase (CEI). In NCM811||Si/C full cells, this additive effectively compensates for irreversible lithium loss, yielding a high initial energy density of 483.84 Wh kg^-1 and superior cycling stability with 80.42% capacity retention after 170 cycles. This work provides an effective interface-engineering strategy to overcome the intrinsic barriers of LiF-based materials, offering a promising prelithiation solution for next-generation high-energy-density batteries.